month = 3
if month==1 or month ==3 or month== 5 or month ==  7 or month ==8 or month== 10 or month ==12
    print(“这个月有31天”)
elif month ==4 or month ==6 or month==9 or month==11
    print(“这个月有30天·”)
elif month ==2
    print(“这个月有28天”)